.main{
    height: 100%;
}

.head-menu{
    width:100%;
    height:50px;
    background: #4d90fe;
    position: fixed
}


.left-menu{
    background: #515a6e;
    padding-top:50px;
    float:left;
    height: 100%;
}

.box{
    width:100%;
    height: 100%;
    padding-top:50px;
    padding-left:240px;
}